The Host Certificate is a X.509 certificate used by the TLS server only and is required.
To create the new Host Certificate click the Edit link below the Host Certificate portion of the menu. This will open up a new window containing the required fields for this new certificate.
Once all the fields have been completed click Create Certificate to create this new CA.
Once a Host Certificate is created it should only be deleted when you want to start over again. Re-creating the Host Certificate will replace the prior host certificate.
Once the Host Certificate is created it will be listed below in the Certificate Authority section.